Modeling and simulation of tree wraps and microsprinkler irrigation for young Citrus freeze protection. I. Model development and validation
1988
Rieger, M. | Smerage, G.H. | Davies, F.S. | Jackson, L.K.
A dynamic heat transfer model was developed for simulation of freeze protection of young citrus trees by tree wraps and microsprinkler irrigation. Heat exchange at the surface of the tree wrap was a function of heat input from irrigation and heat losses to evaporation, radiation, and convection. A finite difference form of a transient heat conduction equation was used to calculate rates of trunk temperature change as a result of heat exchange at the wrap surface. Predicted trunk temperatures were generally within 1 SE of observed means when simulating the effects of tree wraps without irrigation, with high correlation (r = 0.99) between observed and predicted minimum temperatures. When simulating the effects of microsprinkler irrigation combined with tree wraps, however, predicted trunk temperatures were generally 1 degree to 3 degrees C lower than observed means (r = 0.81). Under-prediction of trunk temperature was attributed to underestimation of sensible heat transfer from the irrigation water and/or inaccuracies in parameters associated with irrigation. The behavior of the real and model systems was qualitatively similar in a majority of validation trials. Thus, the simulation model could be used to analyze factors affecting freeze protection.
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